A study of around 150 adults in Canada that were around 50 years old and were either marijuana users, tobacco smokers, or non-smokers shows that marijuana smokers are slightly more likely to develop lung disease than cigarette users. Three-quarters of the marijuana users had emphysema compared to two-thirds of tobacco users.
Study author Dr. Giselle Revah with the University of Ottawa says she was surprised by the results. One limitation of the study could affect the results, though; most of the cannabis users were also either current or former tobacco smokers.
Source: Daily Mail